The frieze-block (circular) vents are commonly used in the open-eave construction shown here. Vents in the eave are vulnerable to the entry of embers (from the wildfire and / or burning landscaping vegetation), and flame (from near-home vegetation, or upward flame spread from combustible siding). Studies have shown that the 1/4" or 1/8" mesh screens typically used with these vents will still allow the passage of embers large enough to result in the ignition of fine fuels in the attic. These vents used 1/8" mesh screens. Vents designed to resist ember and flame intrusion have been developed, and are available in some locations.